It rested with our government, therefore, as the agent of national defence and the representative of national dignity and interests, to apply a remedy. Of course, too, all the pressure of warlike sentiment among our people, especially in the President's party, and even the pressure of motives distinctly selfish, had to be recognized more or less, for such is the nature of popular government. Very likely Polk's abandoning a part of our Oregon claim rendered it the more necessary to avoid flinching in the Mexican affair; and accordingly on April 21, 1846, after long consideration of the matter, he informed the Cabinet that our relations with Mexico "could not be permitted to remain" as they were, and that he thought he should recommend to Congress the adoption of energetic measures for the redress of our grievances, which meant also of course a full settlement of our differences with that power. In truth no other course would have been patriotic or even rational.[6.35] VII THE PRELIMINARIES OF THE CONFLICT April, 1845-April, 1846 Strangely enough, although our diplomatic troubles with Mexico would almost certainly have led to hostilities, the war actually came about in a totally different way.[7.1] During the spring and early summer of 1845, in view of Mexican threats and of reports from trustworthy sources that an invasion of Texas might be expected,[7.2] it was decided by our government that when her people should have accepted our annexation proposal, as they were almost sure to do, it would become the duty of the United States to defend her;[7.3] and this decision made the question where her southern boundary lay a practical matter. It was a thorny subject. In 1834 Mexico herself did not feel sure about the line; and according to the chief technical officer in our state department, sole commissioner to negotiate the treaty of peace with Mexico, if an official demarcation had existed, the war between Texas and the mother-country had rubbed it out. The former now claimed the territory as far as the Rio Grande, but she did not establish her title by occupying completely and effectively the region south of the Nueces. Only by an agreement with Mexico, indeed, could limits have been fixed. So far as it concerned the republic of Texas, this was in effect the situation.[7.4]